Regulating system



Aug. 23, 1932. E. GRAU 1,873,641

REGULATING SYSTEM Filed April 17, 1951 WITNESSES INVENTOR Ernsz 67221:

Patented Aug. 23, 1932 UNITED STATES-VPATENT- OFFICE ERNST enAu, ornnanrN-cmnmrrnmarme, GERMANY, AssxoNoa T0 WESTINGHOUSE ELECTRIC &MANUFACTURING comrANY, A conroBA'rIoN or PENNSYLVANIA BEGULATING SYSTEMApplication filed April 17, 1931, Serial No. 580,761, and in GermanyApril 25, 1980.

;. a resistor.

In regulators of the vibrating type, relays controlled by the regulatorare provided for the purpose of periodically short circuiting a portionof the shunt-field resistor of the machine being regulated, or of anexciter as sociated therewith, in response to changes in an electricalquantity, such as machine voltage, which changes affect the duration oftime during which the continuously opening and closing, or vibrating,contact members of the regulator, disposed to control the relays, are inengagement.

It is general practice to energize the actuating coils of such relaysfrom a directcurrent-voltage source because, as is known, auni-directional potential has many advantages for this purpose over analternatingcurrent voltage.

In alternating-current generator applications, direct-current forenergizing the reg.

ulator relays is frequently obtained from the exciter, or from aseparate battery or equivalent independent source. The use of either ofthese sources is, however, undesirable under some conditions. I

If the exciter is employed for this purpose, provision must be made tocompensate for the large variations in the exciter voltage which, as iswell known, varies in accordance with the operation of the regulator.The comensatin means must therefore revent excessive current flowthroughthe relay coils when the exciter voltage is high and insuresuflicient current flow through the relay coils to operate the relayswhen the exciter voltage is low.

The ultilizationof a separate battery, or

other external source of direct-current potential, while moresatisfactory,is expensive if not required for other purposes.

Furthermore, when the vibrating contacts of the regulator, which controlthe intermediate relays, close a direct-current circuit, a

it is desirable that the polarity of the contacts hereversedoccasionally to prevent one of the contacts from becoming pitted, andthe other from building up in a non-uniform manner.

My invention is directed to a regulator system' that avoids these andother difiiculties.

I attain the desired results by the provision of rectifying means forenergizin the intermediate relays from the alternating-current machineor circuit, the voltage of which the regulator is disposed to maintainat a constant value.

It is, accordingly, an object of my invention to provide, invibrating-type regulating systems for alternating-current circuits,

means for energizing the actuating coils of the intermediate relays bydirect-current. of

substantially constant voltage, derived from the alternating-currentcircuit.

It is a further object of my invention to I eliminate the need forvolta-ge-change-compensating means in the energizing circuits of theactuating coils of the intermediate relays of vibratin -typeregulations.

An additiona o ject of my invention is to provide, in a regulator of thetype-described, means for energizing the auxiliary rela s whicheliminates the need for reversing t e pgjlarity of the contact membersof the regua or.

My invention, together with additional 1 objects and advantages willbest be understood from the following description of a specificembodiment thereof, when read in conjunction with the accompanyingdrawing, in which the single figure is a diagrammatic representation ofapparatus organized in accordance with my invention as applied to avoltage regulator of the vibrating type, for governing the excitation ofan alternating current generator.

Referring to the drawing, a single-phase alternating-current generator10 is connected to circuit conductors 11 and 12. The generator 10 isprovided with a field winding 13 that is energized from any suitablesource,

a circuit that includes a regulating resistor 17.

In order to maintain the voltage of generator 10 constant at apredetermined value,

; 13. Coils 19 and 21 of the regulator are as.-

sociated with movable plunger elements, which respectively control,through the well known mechanical linkages shown, the positions offloating or vibrating contacts 22 and 23.

Regulatory action, in such a system, is accomplished by the periodicshunting of a section 24 of rheostat 17 in the exciter-field circuit,through the contacts 25 of an intermediate or auxiliary relay 26, whichis disposed to operate in accordance with the opening and closing ofvibrating contacts 22 and 23, in a well known manner. The usualpolarity-reversing switch 27 is associated with contacts 25 of theintermediate relay. In case the system requires it, one or moreadditional auxiliary relays may be combined therewith, as relay 26 whichis shown as connected in parallel circuit relation to the relay 26. a

To supply the intermediate relay 26 with a direct-current voltage ofsubstantially constant magnitude, I utilize a rectifier 28 connected, asshown, between the coil of the relay 26 and an alternating-currentvoltage, of suitable potential, derived from the generator circuitconductors 11 and 12, through the medium of transformer 30. It will berecognized that this arrangement makes possible the successful operationof relay 26 without the use of voltage-change-compensating means, whichare necessary if the direct-current voltage is derived directly from theexciter terminals.

To make unnecessary the use of a polarityreversing switch, in thecircuit of the vibrating contacts 22 and 23, these contacts are,according to my invention, disposed to control the alternating-currentinput to rectifier 28, instead of the direct-current input circuit ofthe intermediate relays. In the embodiment shown, it will be seen thatcontacts 22 and 23 act to make and break the circuit through whichtransformer 30 energizes the rectifier, and, when so disposed, they passalternatingcurrent rather than direct current, as in all previousregulator connections known to me. Hence, they are not subjected to theundesirable and harmful material-transferring action which their use ina direct-current circuit involves, and polarity-reversing means may bedispensed with.

In operation of the regulating system, arranged as illustrated, theposition of floatin contact member 22 is determined by the v0 tage ofgenerator 10, this contact member tending to move upwardly, away fromthe cooperating contact member 23, when the voltage is below normal, anddownwardly, toward contact 23, when the voltage is above normal. Theposition of the floating contact member 23 is determined by themagnitude of the voltage of the exciter 14, high exciter voltagestending to bring it into engagement with contact 22 and low excitervoltages allowing it to move downwardly out of engagement therewith.

As is known, the rontacts of a vibrating regulator of the typeillustrated, alternately engage and separate. Engagement of the contacts22 and 23 efiects an operation of the relay 26 to increase theresistance in the exciter field circuit, and lower the voltage of theexciter 14. As the voltage of the exciter l4 and, consequently, of thegenerator 10, decreases, the energization of the windings 19 and 21 areboth decreased to cause contact 22 to move upwardly and contact 23 tomove downwardly, thereby effecting disengagement. This, in turn, acts toagain decrease the resistance in the exciter field circuit, therebycausing the exciter voltage to again rise, and the operation justdescribed is repeated to vary the effective value of the resistor 17 inaccordance with the voltage of the generator 10.

In the system illustrated, closure of the vibrating contacts 22 and 23impresses an alternating-current voltage between points 32 and 33 of therectifier assembly 28. By action of the rectifier, thisalternating-current voltage is converted into a pulsating direct-currentvoltage between points 34 and 35 thereof, which, in the particulararrangement shown, have relatively positive and negative potentials.This direct-current voltage energizes the actuating coil of theintermediate relays, 26 and 26, causing them to open their contacts andthereby remove the short circuit from section 24 of the resistor 17 Theincreased resistance in the field circuit of the exciter lowers thecurrent through field winding 16, thereby lowering the exciter voltageand causing contact 23 to move from engagement with the contact 22. Thisaction will deenergize the rectifier 28 and control the relay 26, asdescribed above.

In practice, rectifier 28 may be of any suitable type, preferably of thefull-wave capacity. In my invention, I prefer to utilize the well knowncopper, copper'oxide disc type, which is schematically represented inthe diagram. Each of the four branches there shown comprises a unitwhich is capable of conducting current only in the direction indicatedby the arrows and the operation already described is thereby attained.

As is known, rectifiers of this construction are exceedingly reliable intheir operation, since they are of a relatively simple and effectiveconstruction, and, furthermore, have the advantage of low cost andsmall'maintenance.

It will be seen that the reliability of the system of my invention isexceedingly high, since the auxiliary relays are assured of asubstantially constant. direct-current voltag supply, so long as thealternating-current generator being regulated continues in normaloperation. Failure of the generator voltage, therefore, is practicallythe only condition under which the supply for the auxiliary relays wouldbe cut off, inwhich case, no damage could result.

It will be seen that, through the system of my invention, I haveprovided a simple, effective and highly reliable means of supplying adirect-current voltage to the auxiliary relays of vibrating-typeregulators when applied to. alternating-current machines or circuits,which, in addition, eliminates the need for the usual polarity-reversingswitch in connection with the floating contacts of the regulator.

Although I have shown and described a specific embodiment of myinvention, I am fully aware that many modifications thereof arepossible. My invention, therefore, is not to be restricted exceptinsofar as is necessitated by the prior art and by the spirit of theappended claims.

I claim as my invention:

1. In a regulator system, an alternatingcurrent circuit and a generatorconnected thereto, means for governing the excitation of said generatorcomprising a resistor, a regulator having vibrating contact membersactuated in accordance with the voltage of said circuit, a rectifierenergized from an alternating-current source in accordance with theaction of said regulator, and a relay energized by direct current fromsaid rectifier for controlling the effective value of said resistor.

2. In a regulator system, an alternatingcurrent circuit, and a generatorconnected thereto, provided with a field winding, means for governingthe excitation of said generator comprising a regulator actuated inaccordance with the voltage of said circuit, a rectifier energized froman alternating-cur.- rent source in accordance with the action of saidregulator, and means energized by direct current from said rectifier forcontrolling the energization of said field winding.

4 In a regulator system, an alternatingcu-rrent circuit and a eneratorconnected thereto, means for governing the excitation of said generatorcomprising a regulator of the vibrating type and a resistor controlledthereby, relays for effecting said control of the resistor, and meansfor energizing said relays from the alternating-current circuitcomprising a current rectifier disposed intermediate said circuit andthe relays.

4:. In alternating-current circuit regulating systems of the vibratingtype comprising voltage-adjusting means, relays disposed to act uponsaid adjusting means, and regulator contact members responsive to thevoltage of said circuit and disposed to control the actuation of said.relays, means for energizing the said relays from the circuit voltagewhich the regulator maintains constant, said means comprising acurrent-rectifier and connecting circuits therefor so disposed that thesaid regulator contact members are connected ahead of the rectifier tothus act in the alternating-current connecting circuit.

5. In a regulator for maintaining a source of alternating-currentvoltage of desired potential comprising, in combination, vibratingcontact members and auxiliary relays controlled thereby, means forenergizing said auxiliary relays from said alternating-current voltagesource comprising a currentrectifying device disposed in a connectionbetween said voltage source and said relays to a supply a substantiallyconstant direct-current voltage thereto.

6. In a regulator for an alternating-current voltage source, thecombination comprising auxiliary relays, vibrating-contact control meanstherefor, and a current rectifier disposed in a connection between saidalternating-current voltage source and said auxiliary relays to supplythereto a directcurrent energizing voltage.

7. In combination, an alternating-current generator provided with afield winding and a direct-current exciter therefor, a shunt fieldwinding for said exciter and a resistance in series circuit therewith,one or more relays for short-circuiting portions of said resistance, anenergizing circuit for said relays,

a current rectifier in said circuit disposed for energization from saidalternating-current generator, and vibrating-contact regulatorcontrolmeans actuated in accordance with 'the voltage of said generator anddisposed current-rectifying device and circuits associated therewith.

9. In combination with an alternatingcurrent generator and a regulatorcomprising cooperating contact members, windings for causing saidcontacts to engage and be disengaged, and auxiliary relays controlled bysaid contact members, a current-rectifying device, and means forconnecting said device between said generator and said auxiliary relays,said current rectifier functioning to supply a direct-current energizingvoltage to the relays.

10. In a vibrating-type regulator for governing the field excitation ofan alternatingcurrent dynamo-electric machine in response to the voltagevariation of said machine, the combination comprising vibrating contactmembers, a machine-excitation-controlling resistor, a plurality ofrelays of the directcurrent type disposed to short circuit sections ofsaid resistor, a current rectifier energized from the voltage of saidalternatingcurrent machine in accordance with the action of saidvibrating-contact members of the regulator, and means whereby saidrelays are energized by direct-current from said rectifier.

In testimony whereof, I have hereunto subscribed my name this 4th day ofMarch 1931.

ERNST GRAU.

